class BookShelf {
    public static void main(String[] args) {
        Book book1 = new Book();
        Book book2 = new Book();
        Book book3 = new Book();
        book1.setName("JAVA");
        book1.setPublishingDate("2019.3.8");
        book1.setWriter("小阿");
        book1.setPublishingHouse("清华大学");
        book2.setName("密码学");
        book2.setPublishingDate("2018.4.8");
        book2.setWriter("艾什");
        book2.setPublishingHouse("北电");
        book3.setName("数据结构与算法");
        book3.setPublishingDate("2013.1.1");
        book3.setWriter("乔纳森乔斯达");
        book3.setPublishingHouse("中广");
        System.out.println(book1.toString());
        System.out.println(book2.toString());
        System.out.println(book3.toString());
    }
}